By Frank Thurston Green

Naming the street you live on would be like naming the back of your hand. The signs staked at modern intersections are a weird shorthand for the landmarks locals actually use to find their way around—for the cafe, for the dumpster painted like a cow, for their neighbor’s green door.

Signs are for outsiders. They’re for tourists and invading armies and GPS satellites. But originally, they were for governments. The bureaucrat and the tax collector were the original outsiders. They put up signs for themselves.

European states started labeling streets and numbering houses back in the 18th century to better track their citizens—to better tax, conscript, and govern them, explained Reuben Rose-Redwood, professor of geography at the University of Victoria. States can’t control what they can’t count.

So when the Soviet Army led the occupation of Prague some two hundred years later, the locals unraveled that statecraft. When they got word that the occupiers planned mass arrests, they destroyed the street signs and house numbers. They made their city an open secret.

“Anyone who was not born here, who has not lived here, will find a city of anonymity among a million inhabitants,” wrote Lidova Demokracie, a Czechoslovak newspaper. “The mailman will find you, but evil-doers won’t!”

There’s nothing intrinsically useful about a street with a name on a stick, even if every intersection has one. The names become powerful when all of them are gathered into a map, to give people a bird’s eye view of how all the signs relate to one another. Street signs stand aloof from local people’s lives, but that goes with their constancy, their reliability. Locals might tell you to turn right at the mango tree, but what if the tree gets chopped down?

Signs are helpful even without maps, though, if they’re staked in a predictable, patterned layout. Take Manhattan. Moving one block north generally yields up a sign with a number one higher. Four left turns land you back where you started. Manhattan’s grid is too big for a person to navigate solely by the landmarks stowed in their mind, but it’s simple enough to not even need a sign at every numbered intersection, said Craig Berger, a researcher at the Signage Foundation. “I’m sure we’ve already lost signs and people haven’t noticed they’re gone,” he said.

If the Russians invade, DIY resistance is futile.

Meanwhile, most everyone in London gets lost without a map to lead them by the nose. The city’s mostly made up of villages that glommed together as they expanded. Those villages arose independently, each with its own distinct layout. With or without a sign on a corner, people living in a disjointed city like London can’t apprehend any neighborhood but their own, Berger explained.

“Streets signs are only meant to support a logic. If there’s no logic to the system, you could have thousands of street signs,” Berger said. “You’d still be equally lost.”

And so in Japan, where the cities are laid out as crazily as London is, streets are rarely named. That’s rooted in Japan’s historically lax laws about where people could build. You could sell someone a strip of land from your backyard and they could build a house there. And whatever nook or alley their door opened onto was its “street.” The house created it.

Streets in Japan aren’t locations in themselves but the boundaries that divide neighborhoods, explained André Sorensen, professor of urban geography at the University of Toronto. In New York, a street like Fifth Avenue sweeps uninterrupted for miles, a channel uniting the people along it in misery or contentment. In Japan, neighborhoods are the geographical unit. And they’re small enough for the locals to know every nook, however crazily laid out. Life is local. Each neighborhood has its own policeman who works out of a miniature, one-man station called a koban— “and people still use them to get directions,” Sorensen said.

Koban or no, GPS is obliterating the particulars of how people find their way around. The lost often abdicate their senses to their gadgets, looking down at their phones to look up at satellites to tell them what to do, and not at their surroundings.

But Manhattan is a different, uniquely navigable place, argued Syed Shah, who’s driven a cab in New York for 20 years. On its uncompromising grid, he said he needs no map or GPS. “You don’t need nothing if you have a little bit of common sense,” he said. “It’s on my fingertips.”

Though Shah, 64, who said he worked in the past as an engineer on navigation systems for Pakistan International Airlines, may not be the most representative person to ask. But his mental map is moot. Most of his passengers these days, smartphone in hand, insist on the route he takes. He likes that. When the inevitable traffic crops up, they can’t blame him.

“It is their own fault,” he said, smiling.